Boom screed machines are used in the paving process to level wet concrete. Boom screed machines include a retractable and extendable boom and a plow head. Extending the boom pushes the plow head over the wet concrete to create a level and smooth surface on the wet concrete.
Chemical sprays, such as evaporation retardants, are often applied to the level and smooth wet concrete to create a protective layer on top of the level and smooth wet concrete. Such, chemical sprays prolong the amount of time available for concrete finishing and also reduce the possibility of surface crusting, surface cracking, and spalling. Typically, such chemical sprays are manually applied to level and smooth wet concrete by handheld sprayers.